The activity and localization of some hydrolytic enzymes during early embryogenesis oflilium regale after pollination with μ-frradiated pollen

I. D. Georgieva

Biologia plantarum 33:337, 1991 | DOI: 10.1007/BF02897684

Changes in the activity and localization of nonspecific esterase, acid phosphatase, α-galactosidase and β-glucosidase inL. regale pistils after pollination with μ-irradiated pollen were studied. In the embryo sac and in the ovule reduction of AS-esterase and α-galactosidase and, at the same time, enhancement of α-esterase, acid phosphatase and β-glucosidase activities were observed. The changes in hydrolytic enzyme activities are discussed as manifestations of lethal factors resulting from structural disturbances of DNA in the generative nucleus and in sperms caused by irradiation.

Photodestruction of Chlorophyll inZea mays L. Leaves Under Different CO₂ Concentration

Z. Lechowski, J. Białczyk

Biologia plantarum 33:345, 1991 | DOI: 10.1007/BF02897685

Photodestruction of chlorophyll (Chl) inZea mays leaves, after their irradiation with high photon fluence rate (5000 μmol m^-2 s{-1}), was determined in fragments of whole leaves (WL) and also in fraction of mesophyll cells (MC) and bundle sheath cells (BSC) after their mechanical separation. The lag phase and the phase of photooxidation of Chl in MC chloroplasts were shorter than in BSC. Duration of both phases was reduced when the leaves were placed in 0 % CO₂ concentration in the atmosphere, while the increase of CO₂ concentration up to 0.3 % totally protected Chl against photodestruction in BSC within the...

Water and Osmotic Potentials of Ethephon-Treated Maize Genotypes Varying in Drought Resistance

W. P. Lu, M. B. Kirkham, C. E. Wassom

Biologia plantarum 33:354-357, 1991 | DOI: 10.1007/BF02897686

Leaves of drought-resistant and drought-sensitive genotypes of maize (Zea mays L.) were sprayed with ethephon to determine its effect on water and osmotic potentials. With both sufficient and limited water supplies, ethephon decreased the water potential, but not the osmotic potential, of the drought-sensitive maize. It had no effect on the water and osmotic potentials of the drought-resistant maize under either water regime. The results showed that the response of a genotype of maize to ethephon depends upon its susceptibility to drought.

An immunochemical testing of pathophysiological reactions of several PSTVinfected tomato (Lycopersicon esculentum L.) cultivars

J. MatouŠek, J. Schubert, M. J. BeneŠ, S. Píša

Biologia plantarum 33:358, 1991 | DOI: 10.1007/BF02897687

Several tomato cultivars were infected with a severe strain of PSTV and a pathophysiological reaction was characterized by means of enzyme-linked immunosorbent assay with serum containing IgGs to disease-associated host-specific leaf proteins. A strong expression of disease-associated symptoms (stunting, epinasty, leaf blade malformation and rugosity) and strong immunochemical reaction was found for cultivars Bizon, Linia, Revermun and Rutgers. The immunochemical assay revealed appearence of a major antigenic protein having a molecular mass of about 70 kD in these cultivars. The immunochemical reaction with disease-associated proteins reached a maximum...

Simultaneous Study of NH⁺₄, Na⁺, Mg²⁺, Ca²⁺, NO^2-₃, SO^2-₄, (NO^-₂), H{2in}PO^-₄ and CI^- Uptake by Intact Winter Wheat Seedlings in a Single Depletion ExperimentPO^-₄ and CI^- Uptake by Intact Winter Wheat Seedlings in a Single Depletion Experiment

I. Matejovič

Biologia plantarum 33:366, 1991 | DOI: 10.1007/BF02897688

Simultaneous uptake of NH⁺ ₄, Na⁺, Mg²⁺, Ca²⁺, NO^- ₃, SO^2- ₄, (NO^- ₂), H²PO^- ₄ and C1^- ions by N-limited winter wheat seedlings(Triticum aestivum L., cv. Regina) in a single depletion experiment was investigated. Individual ion species in uptake solution samples were determined using capillary isotachophoresis. The operating systems used are described in detail. Processing of obtained concentration data allow to construct time curves of individual ions concentration in uptake solution,...

Attempts at Multiplication, Purification, Electron Microscopy, and Characterisation of Three Isolates of the Strawberry Mottle Agent

J. Polák, F. A. Van der Meer, H. Huttinga

Biologia plantarum 33:377, 1991 | DOI: 10.1007/BF02897689

Three isolates of strawberry mottle agent (SMA) from strawberry plants were regularly maintained and multiplied by mechanical inoculation onChenopodium quinoa plants showing mosaic and mottle symptoms. The use of 5 mM borate buffer pH 8.6 or tap water pH 6.6-7.9 with 4 % (m/v) charcoal for homogenization resulted usually in 100 % infection. The total of 2090 plants were infected from 2264 inoculated ones under the same conditions. The infectivity of SMA isolates in crude sap ofC. quinoa was retained from 48 h to 72 h at 20 °C. The dilution end points of SMA isolates were 10^-3 while the inactivation temperatures were between...

Uptake of Lead and Cadmium by Maize Seedlings and the Effect of Heavy Metals on the Activity of Phosphoenolpyruvate Carboxylase Isolated from Maize

Martina Vojtěchová, Sylva Leblová

Biologia plantarum 33:386, 1991 | DOI: 10.1007/BF02897690

Maize seeds and five-day-old maize seedlings were incubated in media containing Pb²⁺ at concentrations of 50, 100, and 200 mg 1^-1 and Cd²⁺ at concentrations of 1, 5, 10 and 50 mg 1^-1. After five days of incubation, both heavy metals were determined by means of AAS following wet mineralisation of roots and shoots. The results obtained indicate that Pb²⁺ were transported to shoots from roots at a lower rate than Cd²⁺.Phosphoenolpyruvate carboxylase (PEPC) isolated from germinating maize seeds was inhibited to a comparable degree by solutions containing 0.001 mmol 1^-1 Pb²⁺,...

Proposed Enzymes of Auxin Biosynthesis and Their Regulation II. Tryptophan Dehydrogenase Activity in Plants.

M. Kutáček, Sultana Terziivanova-Dimova

Biologia plantarum 33:395, 1991 | DOI: 10.1007/BF02897691

In pea, maize and tomato plants a hitherto undescribed L-tryptophan dehydrogenase activity (TDH) has been detected. This enzyme catalyzes the reversible formation of indolepyruvic acid (IPyA) from L-tryptophan (L-trp). TDH and L-glutamate dehydrogenase (GDH), related enzymes in their mode of action, could be separated by gel chromatography. Enzymatic activity of TDH was sustained by both pyridine coenzymes NAD/NADP. With pea TDH the coenzyme NAD displays, at optimum pH 8.5 and at room temperature, only about 40-70 % of the activity of NADP. The amination of IPyA is catalysed more actively than the deamination of L-trp. L-trp/IPyA, L-glu/ketoglutarate,...

Proposed Enzymes of Auxin Biosynthesis and Their Regulation III. Some Properties of Pea Indolylacetaldehyde Oxidase

M. Kutáček, Sultana Terziivanova-Dimova

Biologia plantarum 33:408, 1991 | DOI: 10.1007/BF02897692

Indole-3-acetaldehyde oxidase (IAAld-oxidase) occurs in pea in two forms, of which the first, more active enzyme, has its pH optimum at 4.5, while the second, barely half as active, has a pH optimum at 7.0. Only the pH 4.5 oxidase can be resolved from the acetone powder. Besides IAA1d the more stable IA1d was used as substrate in testing the enzymatic activity. The pea enzyme seems not to be a dismutase since indolylmethanol or indolylethanol were not formed as products. Pyridine nucleotide coenzymes did not activate the partially purified enzyme. The pH 4.5 oxidase was inhibited by more than 50 % by IAA > L-asp > tryptophol > indoleacetylaspartic...

The Utilization of Degree Days for the Characterization of Developmental Stages of 26 Winter Wheat Cultivare

Zdeňka NÁTROVÁ, L. NÁTR

Biologia plantarum 33:417, 1991 | DOI: 10.1007/BF02897693

Twenty six winter wheat cultivars representing early maturing (Em), medium early maturing (Mm), and late maturing (Lm) cultivar groups were grown in the field for two growing seasons. The dates at which plants reached the double ridge (DR) and terminal spikelet (TS) stages were determined using anatomical analysis of shoot apices. Thereafter the dates of anthesis (AN) and full maturity (MA) were recorded. The length of the time spans between subsequent developmental stages was then expressed both chronologically (number of days, d) and in terms of thermal time (degree day, °C d) which was calculated with the basal temperature equalling to zero. The...

Book review

Jarmila Solárová, T. Gichner

Biologia plantarum 33:430-432, 1991 | DOI: 10.1007/BF02897694